JP2018185502A - Micro led display device and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a micro LED display device through which it is possible to implement a display of various sizes.SOLUTION: A micro LED display device includes: a micro LED panel rectangular in plan view in which a plurality of micro LED pixels are arranged in rows and columns; and a micro LED driving board (backplane) 400 including an active matrix (AM) circuit unit 405 having a plurality of CMOS cells corresponding to the plurality of micro LED pixels, and control circuit units 410-480 disposed outside the AM circuit unit. The control circuit unit is disposed adjacent to two of the four surfaces of the micro LED panel.SELECTED DRAWING: Figure 15

Description

  The present invention relates to a micro LED display device and a manufacturing method thereof, and more specifically, to a micro LED display device capable of realizing displays of various sizes and a manufacturing method thereof.

  A light emitting device (LIGHT) is a type of semiconductor device that converts electrical energy into light energy. The light emitting element has advantages of low power consumption, semi-permanent lifetime, quick response speed, safety, and environmental friendliness as compared with existing light sources such as fluorescent lamps and incandescent lamps.

  Therefore, much research has been conducted to replace existing light sources with light-emitting elements. When light-emitting elements are used as light sources for lighting devices such as various lamps, liquid crystal display devices, electric bulletin boards, and street lamps used indoors and outdoors. Has increased.

  Recently, the LED industry has made new attempts to apply LEDs to various industries beyond the range of existing traditional lighting, especially low power drive flexible display, adhesive information display element for human body monitoring Research is being actively conducted in the field of bioreaction and DNA sensing, biofusion for effective photogenetic verification, the field of Photonics Textile in which conductive fibers and LED light sources are combined, and the like.

  In general, if the LED chip is made as small as several to several tens of micro levels, the disadvantage of breaking when bent due to the characteristics of the inorganic material can be overcome, and by transferring the LED chip to a flexible substrate, flexibility (flexibility) is imparted, Not only the flexible display described above but also a wearable device and a medical device for human body insertion can be widely applied to various application fields. However, in order to apply LED light sources to the above-mentioned application fields, it is essential to develop a thin and flexible micro-level light source, and in order to give flexibility to LEDs, for example, thin film GaN layers separated from each other. The process which transfers the LED chip which consists of these to a flexible substrate by individual or desired arrangement is calculated | required.

  On the other hand, the conventional micro LED technology has succeeded in fabricating LED pixel units to several micro size by a semiconductor process, but the size of the micro LED module is limited by the limit of the wafer size. There is a problem. In addition, a product requiring a display of about 1.2 inches or more requires a separate optical module, which not only increases the size of the display module but also causes a problem of reducing light efficiency. Therefore, it is necessary to develop a micro LED module that can realize displays of various sizes.

  The object of the present invention is to solve the aforementioned problems and other problems. In particular, a first object of the present invention is to provide a micro LED display device capable of realizing various sizes of displays by changing the structure of a CMOS backplane and a manufacturing method thereof.

  Another object of the present invention is to provide a micro LED display device and a method for manufacturing the same, which can realize displays of various sizes by changing the structure of the common electrode of the micro LED panel.

  In order to achieve the above or other objects, according to one aspect of the present invention, a plurality of micro LED pixels are arranged in rows and columns, and the micro LED panel is rectangular in a plan view, and the plurality of micro LED pixels. A micro LED driving substrate including an AM (Active Matrix, Active Matrix) circuit unit including a plurality of CMOS cells corresponding to the above and a control circuit unit disposed outside the AM circuit unit, and the control circuit The part is disposed along two adjacent sides of the four sides of the micro LED panel. A micro LED display device is provided.

  The effects of the micro LED display device and the manufacturing method thereof according to the embodiment of the present invention will be described as follows.

  According to at least one of the embodiments of the present invention, various sizes of displays can be realized by changing the structure of the CMOS backplane used in the micro LED display device.

  In addition, according to at least one of the embodiments of the present invention, various sizes of displays can be realized by changing the structure of the common electrode of the micro LED panel used in the micro LED display device.

  According to at least one of the embodiments of the present invention, various sizes of displays can be realized by changing the direction and combining the first type micro LED display device and the second type micro LED display device. There is.

  However, the effects that can be achieved by the micro LED display device and the manufacturing method thereof according to the embodiments of the present invention are not limited to those mentioned above. It is clearly understandable to those with ordinary knowledge.

It is sectional drawing of the micro LED panel by one Embodiment of this invention. It is a top view of the micro LED panel by one Embodiment of this invention. It is a figure explaining the manufacturing method of the micro LED panel by one Embodiment of this invention. It is a figure explaining the manufacturing method of the micro LED panel by one Embodiment of this invention. It is a figure explaining the manufacturing method of the micro LED panel by one Embodiment of this invention. It is a figure explaining the manufacturing method of the micro LED panel by one Embodiment of this invention. It is a figure explaining the manufacturing method of the micro LED panel by one Embodiment of this invention. It is sectional drawing of the micro LED panel by other embodiment of this invention. It is a top view of the micro LED panel by other embodiment of this invention. It is a figure explaining the manufacturing method of the micro LED panel by other embodiment of this invention. It is a figure explaining the manufacturing method of the micro LED panel by other embodiment of this invention. It is a figure explaining the manufacturing method of the micro LED panel by other embodiment of this invention. It is a figure explaining the manufacturing method of the micro LED panel by other embodiment of this invention. It is a figure explaining the manufacturing method of the micro LED panel by other embodiment of this invention. It is a figure explaining the structure of the general CMOS backplane used for a micro LED display apparatus. It is a figure explaining the structure of the CMOS backplane by one Embodiment of this invention. It is a figure explaining the structure of the CMOS backplane by other embodiment of this invention. 1 is a diagram illustrating a micro LED display device according to an embodiment of the present invention. FIG. 5 is a diagram illustrating a micro LED display device according to another embodiment of the present invention. It is a figure explaining the micro LED display apparatus which expanded display size 2 times in the horizontal direction. It is a figure explaining the micro LED display apparatus which expanded display size 2 times in the perpendicular direction. It is a figure explaining the micro LED display apparatus which expanded display size 4 times.

  Hereinafter, embodiments disclosed in the present specification will be described in detail with reference to the accompanying drawings. The same or similar components will be denoted by the same reference numerals regardless of the reference numerals, and overlapping description thereof will be omitted. I will omit it. The suffixes “module” and “part” for the components used in the following description are given or used only in consideration of the ease of preparing the specification, and have the meaning or role distinguished from each other by themselves. It does not have. That is, the term “unit” used in the present invention means a hardware component such as software, FPGA, or ASIC, and “unit” plays a role. However, the “unit” is not a component limited to software or hardware. A “part” may be configured to be in a storage medium that can be addressed, or may be configured to cause one or more processors to play. Thus, by way of example, “parts” are components such as software components, object-oriented software components, class components and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, Includes firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. Functions provided by “parts” as components may be combined to form a smaller number of “parts” as components, or further divided into “parts” as additional components.

  Also, when describing embodiments according to the present invention, each layer (film), region, pattern or structure is “above / over” the substrate, each layer (film), region, pad or pattern, or When described as being formed “below, under”, “upper / upper” and “lower / lower” are “directly” or “indirectly”. Including everything that is formed. References to the upper / upper or lower / lower of each layer will be described with reference to the drawings. In the drawings, the thickness and size of each layer are exaggerated or omitted or schematically illustrated for convenience of description and clarity. Further, the size of each component in the figure does not completely reflect the actual size.

  When describing the embodiments disclosed in the present specification, when it is determined that there is a possibility that a concrete description related to a related known technique may unnecessarily obscure the gist of the embodiments disclosed in the present specification. Will not be described in detail. Further, the attached drawings are only for facilitating understanding of the embodiments disclosed in the present specification, and the technical ideas disclosed in the present specification are limited by the attached drawings. It should be understood that all modifications, equivalents and alternatives included in the spirit and scope of the present invention are included.

  The present invention proposes a micro LED display device capable of realizing various sizes of displays by changing the structure of a CMOS backplane and a manufacturing method thereof. Hereinafter, in the micro LED display device according to the present embodiment, a micro LED panel including a plurality of micro LED pixels and a CMOS backplane including a plurality of CMOS cells for independently driving the plurality of micro LED pixels. It is formed by flip-chip bonding through bumps.

In the following, various embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a cross-sectional view of a micro LED panel 100 according to an embodiment of the present invention, and FIG. 2 is a plan view of the micro LED panel 100 according to an embodiment of the present invention.

  1 and 2, a micro LED panel (or micro LED array) 100 according to the present invention includes a plurality of light emitting elements (that is, a plurality of micro LED pixels) stacked on a wafer in a matrix. The LED panel has an array structure, and functions to output light corresponding to an image signal of an image display device. At this time, the plurality of micro LED pixels are arranged in rows and columns on the wafer, and each pixel has a size of several μm.

  The micro LED panel 100 includes a growth substrate 110, a first conductive semiconductor layer 120 on the growth substrate 110, an active layer 130 on the first conductive semiconductor layer 120, and a second conductive semiconductor layer on the active layer 130. 140, a first conductive metal layer 160 on the first conductive semiconductor layer 120, a second conductive metal layer 150 on the second conductive semiconductor layer 140, and a passivation layer 170.

The growth substrate 110 is made of a light-transmitting material, for example, sapphire (Al ₂ O ₃ ), a single crystal substrate, SiC, GaAs, GaN, ZnO, AlN, Si, GaP, InP, or Ge. However, it is not limited to these.

The first conductivity type semiconductor layer 120 may include a group III-V element compound semiconductor doped with an n-type dopant. Such a first conductive semiconductor layer 120 is, for example, a semiconductor material having a composition formula of In _x Al _y Ga _1-xy N (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1). Specifically, it is selected from InAlGaN, GaN, AlGaN, AlInN, InGaN, AlN, InN, etc., and doped with an n-type dopant such as Si, Ge, Sn.

The active layer 130 is activated by combining electrons (or holes) injected through the first conductive semiconductor layer 120 and holes (or electrons) injected through the second conductive semiconductor layer 140. This is a layer that emits light due to a band gap difference of energy bands corresponding to a material forming the layer 130. The active layer 130 may be formed of any one of a single quantum well structure, a multiple quantum well structure (MQW), a quantum dot structure, or a quantum line structure, but is not limited thereto. The active layer 130 _may be comprised of a semiconductor material having a _{In x Al y Ga 1-x} -y N (0 ≦ x ≦ 1,0 ≦ y ≦ 1,0 ≦ x + y ≦ 1) of the formula. When the active layer 130 is formed with a multiple quantum well structure, the active layer 130 is formed by alternately stacking a plurality of well layers and a plurality of barrier layers.

The second conductivity type semiconductor layer 140 may include a group III-V element compound semiconductor doped with a p-type dopant. Such a second conductivity type semiconductor layer 140 is, for example, a semiconductor material having a composition formula of In _x Al _y Ga _1-xy N (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1). Specifically, it is selected from InAlGaN, GaN, AlGaN, InGaN, AlInN, AlN, InN, etc., and doped with a p-type dopant such as Mg, Zn, Ca, Sr, Ba.

  A second conductivity type metal layer (ie, p electrode) 150 is formed on the second conductivity type semiconductor layer 140, and a first conductivity type metal layer (ie, n electrode) 160 is formed on the first conductivity type semiconductor layer 120. Is formed.

  For example, as shown in FIG. 2, the second conductive metal layer 150 is disposed on the second conductive semiconductor layer 140 corresponding to each micro LED pixel, and each CMOS cell included in the CMOS backplane It is electrically connected via a bump.

  The first conductivity type metal layer 160 is disposed on the mesa-etched region of the first conductivity type semiconductor layer 120 and is spaced apart from the plurality of micro LED pixels by a certain distance. The first conductive type metal layer 160 is formed on the first conductive type semiconductor layer 120 with a predetermined width along the outline of the micro LED panel 100. The height of the first conductive type metal layer 160 is substantially the same as the height of the plurality of micro LED pixels. The first conductivity type metal layer 160 is electrically connected to the common cell of the CMOS backplane by bumps, and functions as a common electrode of the micro LED pixel. For example, the first conductivity type metal layer 160 is a common ground.

  The first conductive metal layer 160 and the second conductive metal layer 150 provide power to a plurality of micro LED pixels formed on the micro LED panel 100.

A passivation layer 170 is formed on at least one side of the first conductive type semiconductor layer 120, the active layer 130, the second conductive type semiconductor layer 140, the first conductive type metal layer 160, and the second conductive type metal layer 150. The passivation layer 170 is formed to electrically protect the light emitting structures 120, 130, and 140, and includes, for example, SiO ₂ , SiO _x , SiO _x N _y , Si ₃ N ₄ , and Al ₂ O ₃ . It is not limited to these.

  Light emitting elements (that is, micro LED pixels) formed in the micro LED panel 100 emit light having different wavelengths according to the composition ratio of the compound semiconductor. When the light emitting element included in the micro LED panel 100 is a red LED element, the micro LED panel 100 is a red LED panel. When the light emitting element included in the micro LED panel 100 is a green LED element, the micro LED panel 100 is a green LED panel. When the light emitting element included in the micro LED panel 100 is a blue LED element, the micro LED panel 100 is a blue LED panel. On the other hand, the micro LED panel 100 can realize a full color by combining an R / G / B phosphor or an R / G / B color filter with a plurality of light emitting elements that output a specific wavelength.

  Flip chip bonding using bumps so that a plurality of micro LED pixels formed on the micro LED panel 100 and a plurality of CMOS cells formed on the CMOS backplane are connected in a one-to-one correspondence. By doing so, a micro LED display device is configured. At this time, the first conductive metal layer 160 and the second conductive metal layer 150 formed on the micro LED panel 100 are electrically connected to the CMOS backplane via the bumps.

3 to 7 are views for explaining a method of manufacturing a micro LED panel according to an embodiment of the present invention.
Referring to FIG. 3, the first conductive semiconductor layer 120, the active layer 130, and the second conductive semiconductor layer 140 may be sequentially grown on the growth substrate 110 to form the light emitting structures 120, 130, and 140. .

The growth substrate 110 is made of a light-transmitting material, for example, sapphire (Al ₂ O ₃ ), a single crystal substrate, SiC, GaAs, GaN, ZnO, AlN, Si, GaP, InP, or Ge. However, it is not limited to these.

The first conductivity type semiconductor layer 120 is a semiconductor material having a composition formula of In _x Al _y Ga _1-xy N (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1), for example, InAlGaN. , GaN, AlGaN, AlInN, InGaN, AlN, InN or the like, and doped with an n-type dopant such as Si, Ge, or Sn. The first conductive semiconductor layer 120 is formed by injecting trimethylgallium (TMGa) gas, ammonia (NH ₃ ) gas, and silane (SiH ₄ ) gas together with hydrogen gas into a chamber. An undoped semiconductor layer (not shown) and / or a buffer layer (not shown) may be further included between the growth substrate 110 and the first conductive semiconductor layer 120, but is not limited thereto.

The active layer 130 _may be made of a semiconductor material having a _{In x Al y Ga 1-x} -y N (0 ≦ x ≦ 1,0 ≦ y ≦ 1,0 ≦ x + y ≦ 1) of the formula. The active layer 130 may be formed by injecting trimethylgallium (TMGa) gas, trimethylindium (TMIn) gas, or ammonia (NH ₃ ) gas into the chamber together with hydrogen gas.

The second conductivity type semiconductor layer 140 is a semiconductor material having a composition formula of InxAlyGa1-xyN (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1), for example, InAlGaN, GaN, AlGaN, InGaN. , AlInN, AlN, InN, etc., and doped with a p-type dopant such as Mg, Zn, Ca, Sr, Ba. For example, the second conductive semiconductor layer 140 includes, for example, trimethyl gallium (TMGa) gas, ammonia (NH ₃ ) gas, bis (ethylcyclopentadienyl) magnesium, {(EtCp) ₂ Mg}. , Or {Mg (C ₂ H ₅ C ₅ H ₄ ) ₂ }) gas is injected into the chamber together with hydrogen gas.

  Referring to FIG. 4, a plurality of light emitting devices are formed by performing an isolation etching process on the light emitting structures 120, 130, and 140 according to a unit pixel region. For example, the isolation etching is performed by a dry etching method such as ICP (Inductively Coupled Plasma). Through the isolation etching process, one upper surface of the first conductive semiconductor layer 120 is exposed. At this time, in order to form the common electrode (that is, the n electrode) 160, the peripheral region of the first conductivity type semiconductor layer 120 is etched to have a predetermined width.

Referring to FIGS. 5 and 6, a second conductive metal layer 150 covering a part of the second conductive semiconductor layer 140 is formed on one upper surface of the second conductive semiconductor layer 140, and the exposed peripheral region is exposed. A first conductive metal layer 160 is formed on one upper surface of the first conductive semiconductor layer 120.
At this time, the first and second conductive metal layers 160 and 150 are formed by a vapor deposition process or a plating process, but are not particularly limited thereto.

  Referring to FIG. 7, a passivation layer 170 is formed on the growth substrate 110, the light emitting structures 120, 130, and 140, the first conductive metal layer 160, and the second conductive metal layer 150, and the first and second conductive layers are formed. The passivation layer 170 is selectively removed so that one upper surface of the mold metal layers 150 and 160 is exposed to the outside. Thereafter, the micro LED panel 100 formed by the above-described process is flip-chip bonded to a CMOS backplane (not shown) to form a micro LED display device.

FIG. 8 is a cross-sectional view of a micro LED panel according to another embodiment of the present invention, and FIG. 9 is a plan view of a micro LED panel according to another embodiment of the present invention.
Referring to FIGS. 8 and 9, the micro LED panel 200 according to the present invention includes an array in which a plurality of light emitting devices (that is, a plurality of micro LED pixels) stacked on a wafer are arranged in a matrix. The LED panel has a structure and functions to output light corresponding to an image signal of an image display device.

  The micro LED panel 200 includes a growth substrate 210, a first conductive semiconductor layer 220 on the growth substrate 210, an active layer 230 on the first conductive semiconductor layer 220, and a second conductive semiconductor layer on the active layer 230. 240, a first conductive metal layer 260 on the first conductive semiconductor layer 220, a second conductive metal layer 250 on the second conductive semiconductor layer 240, and a passivation layer 270.

  In the present embodiment, the growth substrate 210, the first conductive type semiconductor layer 220, the active layer 230, the second conductive type semiconductor layer 240, the first and second conductive type metal layers 250 and 260, and the passivation layer 270 are formed as shown in FIG. Since it is similar to the substrate 110, the first conductive type semiconductor layer 120, the active layer 130, the second conductive type semiconductor layer 140, the first and second conductive type metal layers 150 and 160, and the passivation layer 170, detailed description thereof is omitted. The explanation will focus on the differences.

  A second conductive metal layer (ie, p electrode) 250 is formed on the second conductive semiconductor layer 240, and a first conductive metal layer (ie, n electrode) 260 is formed on the first conductive semiconductor layer 220. Is formed.

  For example, as shown in FIG. 9, the second conductivity type metal layer 250 is disposed on the second conductivity type semiconductor layer 240 corresponding to each micro LED pixel, and each CMOS cell included in the CMOS backplane and It is electrically connected via a bump.

  The first conductive metal layer 260 is formed to have a predetermined width along the left outer region and the lower outer region on the upper surface of the micro LED panel 200, and functions as a common electrode of the micro LED pixel. Meanwhile, as another embodiment (not shown), the first conductive metal layer 260 is formed on the upper surface of the micro LED panel 200 to have a predetermined width along the right outer region and the lower outer region. Functions as a common electrode for pixels. The first and second conductive metal layers 250 and 260 provide power to the plurality of micro LED pixels formed on the micro LED panel 200.

A passivation layer 270 is formed on at least one side of the first conductive type semiconductor layer 220, the active layer 230, the second conductive type semiconductor layer 240, the first conductive type metal layer 260, and the second conductive type metal layer 250. The passivation layer 270 is formed to electrically protect the light emitting structures 220, 230, and 240, and includes, for example, SiO ₂ , SiO _x , SiO _x N _y , Si ₃ N ₄ , and Al ₂ O ₃ . It is not limited to these.

  Flip chip bonding using bumps so that a plurality of micro LED pixels formed on the micro LED panel 200 and a plurality of CMOS cells formed on the CMOS backplane are connected in a one-to-one correspondence. By doing so, a micro LED display device is configured. At this time, the first conductive metal layer 260 and the second conductive metal layer 250 formed on the micro LED panel 200 are electrically connected to the CMOS backplane through the bumps.

  FIGS. 10-14 is a figure explaining the manufacturing method of the micro LED panel based on the said other embodiment of this invention. Hereinafter, in the present embodiment, since the micro LED panel manufacturing method is similar to the micro LED panel manufacturing method of FIGS. 3 to 7, detailed description thereof will be omitted, and the difference will be mainly described.

  Referring to FIG. 10, the first conductive semiconductor layer 220, the active layer 230, and the second conductive semiconductor layer 240 are sequentially grown on the growth substrate 210 to form the light emitting structures 220, 230, and 240.

  Referring to FIG. 11, a plurality of light emitting devices (ie, a plurality of micro LED pixels) are formed by performing an isolation etching process on the light emitting structures 220, 230, and 240 according to a unit pixel region. To do. For example, the isolation etching is performed by a dry etching method such as ICP (Inductively Coupled Plasma). Through the isolation etching process, one upper surface of the first conductive semiconductor layer 220 is exposed.

  Referring to FIGS. 12 and 13, a second conductive metal layer 250 covering a part of the second conductive semiconductor layer 240 is formed on one upper surface of the second conductive semiconductor layer 240 and mesa-etched. A first conductive metal layer 260 may be formed on one upper surface of the first conductive semiconductor layer 220. Unlike the manufacturing process of FIGS. 5 and 6, the first conductive metal layer 260 is formed only in a partial region of the peripheral region of the first conductive semiconductor layer 220. At this time, the first and second conductive metal layers 260 and 250 are formed by a vapor deposition process or a plating process, but are not particularly limited thereto.

  Referring to FIG. 14, a passivation layer 270 is formed on the growth substrate 210, the light emitting structures 220, 230, and 240, the first conductive metal layer 260, and the second conductive metal layer 250, and the first and second conductive layers are formed. The passivation layer 270 is selectively removed so that one upper surface of the mold metal layers 260 and 250 is exposed to the outside. Thereafter, the micro LED panel 200 formed by the above-described process can be flip-chip bonded to a CMOS backplane (not shown) to form a micro LED display device.

FIG. 15 is a diagram for explaining the structure of a general CMOS backplane used in a micro LED display device.
Referring to FIG. 15, a general CMOS backplane (or micro LED driving substrate) 400 is disposed to face the micro LED panel 100, and is provided in the micro LED panel 100 corresponding to an input image signal. It serves to drive a plurality of micro LED pixels.

  The CMOS backplane 400 includes an active matrix circuit unit 405 including a plurality of CMOS cells for individually driving a plurality of micro LED pixels, and a control circuit unit disposed outside the active matrix circuit unit 405. 410-480.

  Each of the plurality of CMOS cells provided in the active matrix circuit portion 405 is electrically connected to a corresponding micro LED pixel through a bump. Therefore, each of the plurality of CMOS cells is, for example, a pixel driving circuit including two transistors and one capacitor. When the micro LED panel 100 is flip-chip bonded to the CMOS backplane 400 using bumps, it is equivalent. On the circuit, each micro LED pixel is arranged between the drain terminal of the transistor of the pixel driving circuit and the common ground terminal.

  The CMOS backplane 400 includes a common cell (not shown) formed at a position corresponding to the first conductive type metal layer 160 of the micro LED panel 100. The first conductive type metal layer 160 and the common cell are connected via bumps. Electrically connected.

  The control circuit unit includes a scan driver 410, a first data driver 420, a second data driver 430, a gamma voltage generator 440, a timing controller 450, a scan signal detection pad unit 460, a data output detection pad unit 470, and an input. A pad portion 480 is included.

  The circuits 410 to 480 constituting the control circuit unit are arranged in a region adjacent to the four sides (that is, the upper / lower / left / right sides) of the active matrix circuit unit 405 arranged in a rectangle. As an example, as shown in the drawing, the scan driver 410 is arranged in the left region of the active matrix circuit unit 405, and the scan signal detection pad unit 460 is arranged in the right region of the active matrix circuit unit 405. In addition, the data output detection pad unit 470 is disposed in an area above the active matrix circuit unit 405, and the first and second data driving units 420 and 430, the gamma voltage generation unit 440, the timing control unit 450, and the input pad unit 480 are provided. It is arranged in a region below the active matrix circuit portion 405.

  In response to the gate timing control signal (GDC) supplied from the timing controller 450, the scan driver 410 generates a swing level of the gate driving voltage so that the transistors corresponding to the plurality of micro LED pixels can operate. Scan signals are sequentially generated while shifting the signals. The scan driver 410 supplies a scan signal generated through the scan line to a plurality of micro LED pixels included in the micro LED panel 100.

  The first and second data drivers 420 and 430 sample and latch the digital data signal supplied from the timing controller 450 in response to the data timing control signal (DDC) supplied from the timing controller 450. To convert the data into a parallel data structure. The first and second data drivers 420 and 430 convert the digital data signal into a gamma reference voltage and output an analog data signal when converting the data into parallel data. The first and second data drivers 420 and 430 supply the analog data signals to a plurality of micro LED pixels included in the micro LED panel 100 through data lines. Here, the first data driver 420 supplies a data signal to the micro LED pixels existing in the left region of the micro LED panel 100, and the second data driver 430 exists in the right region of the micro LED panel 100. Supply to micro LED pixel.

  The gamma voltage generator 440 generates a gamma reference voltage and provides it to the first and second data drivers 420 and 430.

  The timing controller 450 is supplied with a vertical synchronization signal (Vsync), a horizontal synchronization signal (Hsync), a data enable signal (Data Enable, DE), a clock signal (CLK), a data signal (DATA), and the like from the outside. The timing controller 450 uses the timing signal such as the vertical synchronization signal (Vsync), the horizontal synchronization signal (Hsync), the data enable signal (Data Enable, DE), the clock signal (CLK), and the like to generate the first and second data. The operation timings of the drive units 420 and 430 and the scan drive unit 410 are controlled.

  The control signal generated from the timing controller 450 controls the gate timing control signal (GDC) for controlling the operation timing of the scan driver 410 and the operation timing of the first and second data drivers 420 and 430. A data timing control signal (DDC) is included.

  The gate timing control signal (GDC) includes a gate start pulse (Gate Start Pulse, GSP), a gate shift clock (Gate Shift Clock, GSC), and a gate output enable signal (Gate Output Enable, GOE). The data timing control signal (DDC) includes a source start pulse (Source, Start Pulse, SSP), a source sampling clock (Source Sampling Clock, SSC), and a source output enable signal (Source Output Enable, SOE).

  The scan signal detection pad unit 460 includes pads (pads) for detecting a scan signal output from the scan driver 410. The data output detection pad unit 470 includes pads for multiplexing data signals output from the first and second data driving units 420 and 430 and detecting the multiplexed data signals.

  The input pad unit 480 is a pad for inputting an external signal, and includes an RGB input pad unit, an LVDS (Low voltage differential signaling) input pad unit, and an SPI (Serial Peripheral Interface) input pad unit.

  If the control operation of the micro LED panel 100 via the CMOS backplane 400 is briefly seen, the scan driver 410 scans all the scanning lines when providing image data, and sets one or more of them. An H (high) signal is input to turn on. Meanwhile, when image data is supplied from the first and second data drivers 420 and 430 to a plurality of data lines, only the micro LED pixels placed in a turned-on state in the scanning line receive the image data, and the image data Is displayed via the micro LED panel 100. In this manner, all the scanning lines are sequentially scanned, and the display for one frame is completed.

  The micro LED panel 100 is flip-chip bonded on the CMOS backplane 400 to form a micro LED display device.

FIG. 16 is a diagram illustrating the structure of a CMOS backplane according to an embodiment of the present invention.
Referring to FIG. 16, a CMOS backplane (or first type CMOS backplane) 500 according to an embodiment of the present invention is disposed to face the micro LED panel 200 and corresponds to an input image signal. The micro LED panel 200 has a function of driving a plurality of micro LED pixels.

  The CMOS backplane 500 includes an active matrix circuit unit 505 including a plurality of CMOS cells for individually driving a plurality of micro LED pixels, and control circuit units 510 to 580 disposed outside the active matrix circuit unit 505. including.

  Each of the plurality of CMOS cells provided in the active matrix circuit portion 505 is electrically connected to a corresponding micro LED pixel through a bump. The CMOS backplane 500 includes a common cell (not shown) formed at a position corresponding to the first conductive type metal layer 260 of the micro LED panel 200, and the first conductive type metal layer 260 and the common cell are connected via bumps. Are electrically connected.

  The control circuit unit includes a scan driver 510, a first data driver 520, a second data driver 530, a gamma voltage generator 540, a timing controller 550, a scan signal detection pad unit 560, a data output detection pad unit 570, and an input. A pad portion 580 and the like are included.

  In this embodiment, the scan driver 510, the first data driver 520, the second data driver 530, the gamma voltage generator 540, the timing controller 550, the scan signal detection pad unit 560, and the data constituting the control circuit unit. The output detection pad unit 570 and the input pad unit 580 are respectively the scan driver 410, the first data driver 420, the second data driver 430, the gamma voltage generator 440, the timing controller 450, and the scan signal shown in FIG. Since it is the same as the detection pad unit 460, the data output detection pad unit 470, and the input pad unit 480, detailed description thereof will be omitted.

  On the other hand, unlike the general CMOS backplane 400 shown in FIG. 15, the circuits 510 to 580 constituting the control circuit unit according to the present embodiment include the first side ( That is, it is arranged only in a region adjacent to the left side) and the second side (that is, the lower side). In this case, the CMOS backplane 500 can share a common electrode (that is, n electrode) on the micro LED panel 200 corresponding to the region where the circuits 510 to 580 are disposed.

  As an example, as shown in the drawing, the scan driver 510 and the scan signal detection pad unit 560 are arranged adjacent to the left region of the active matrix circuit unit 505. More specifically, the scan driving unit 510 is disposed adjacent to the left side of the active matrix circuit unit 505, and the scan signal detection pad unit 560 is disposed adjacent to the left side thereof.

  The first and second data driving units 520 and 530, the gamma voltage generation unit 540, the data output detection pad unit 570, the timing control unit 550, and the input pad unit 580 are disposed adjacent to the region below the active matrix circuit unit 505. Is done. More specifically, the data output detection pad unit 570 is disposed adjacent to the lower side of the active matrix circuit unit 505, and the first and second data driving units 520 and 530 and the gamma voltage generation unit 540 are disposed adjacent to the lower side thereof. And an input pad portion 580 is arranged adjacent to the lower side thereof. In addition, the timing control unit 550 is disposed in a left adjacent area of the data output detection pad unit 570 and the first data driving unit 520.

  On the other hand, the arrangement form and the detailed position of the circuits 510 to 580 arranged adjacent to the two sides of the active matrix circuit unit 505 are not limited to the circuit arrangement shown in the drawing, and the customer's requirements or the manufacturer's design matters It will be apparent to those skilled in the art that the position can be changed according to the above.

  A micro LED panel 200 is flip-chip bonded on such a CMOS backplane 500 to form a first type micro LED display device. At this time, the first type micro LED display device can be manufactured up to 1.22 inches.

FIG. 17 is a diagram illustrating the structure of a CMOS backplane according to another embodiment of the present invention.
Referring to FIG. 17, a CMOS backplane (or second type CMOS backplane) 600 according to another embodiment of the present invention is shown in the drawing with respect to the micro LED panel 200 shown in FIG. 16 described above. The micro LED panel 300 (not shown) that is a left and right mirror image object is disposed so as to face each other, and functions to drive a plurality of micro LED pixels provided in the micro LED panel 300 in response to an input image signal.

  The CMOS backplane 600 includes an active matrix circuit unit 605 including a plurality of CMOS cells for individually driving a plurality of micro LED pixels, and control circuit units 610 to 680 disposed outside the active matrix circuit unit 605. including.

  Each of the plurality of CMOS cells provided in the active matrix circuit unit 605 is electrically connected to a corresponding micro LED pixel through a bump. The CMOS backplane 600 is disposed at a mirror image symmetrical position on the first conductive metal layer 360 of the micro LED panel 300 (not shown, and with the first conductive metal layer 260 of the micro LED panel 200 in plan view). ), And the first conductive metal layer 360 and the common cell (not shown) on the CMOS backplane 600 are electrically connected via bumps. Is done.

  The control circuit unit includes a scan driver 610, a first data driver 620, a second data driver 630, a gamma voltage generator 640, a timing controller 650, a scan signal detection pad unit 660, a data output detection pad unit 670, and an input. A pad portion 680 and the like are included.

  In the present embodiment, a scan driver 610, a first data driver 620, a second data driver 630, a gamma voltage generator 640, a timing controller 650, a scan signal detection pad unit 660, and data constituting the control circuit unit. The output detection pad unit 670 and the input pad unit 680 are the scan driver 410, the first data driver 420, the second data driver 430, the gamma voltage generator 440, the timing controller 450, and the scan signal detector of FIG. Since it is the same as the pad unit 460, the data output detection pad unit 470, and the input pad unit 480, detailed description thereof will be omitted.

  On the other hand, unlike the general CMOS backplane 400 shown in FIG. 15, the circuits 610 to 680 constituting the control circuit unit according to the present embodiment include the first side (that is, the right side) and the active matrix circuit unit 605. It is arranged only in a region adjacent to the second side (that is, the lower side). In this case, the CMOS backplane 600 can share a common electrode (that is, n electrode) on the micro LED panel 300 corresponding to the region where the circuits 610 to 680 are disposed.

  As an example, as illustrated in FIG. 17, the scan driving unit 610 and the scan signal detection pad unit 660 are disposed adjacent to the right region of the active matrix circuit unit 605. More specifically, the scan driving unit 610 is disposed adjacent to the right side of the active matrix circuit unit 605, and the scan signal detection pad unit 660 is disposed adjacent to the right side.

  The first and second data driving units 620 and 630, the gamma voltage generation unit 640, the data output detection pad unit 670, the timing control unit 650, and the input pad unit 680 are disposed adjacent to a region below the active matrix circuit unit 605. Is done. More specifically, the data output detection pad unit 670 is disposed adjacent to the lower side of the active matrix circuit unit 605, and the first and second data driving units 620 and 630 and the gamma voltage generation unit 640 are disposed adjacent to the lower side thereof. The input pad portion 680 is disposed adjacent to the lower portion thereof. In addition, the timing control unit 650 is disposed in a right adjacent area of the data output detection pad unit 670 and the first data driving unit 620.

  On the other hand, the arrangement form and the detailed position of the circuits 610 to 680 arranged adjacent to the two sides of the active matrix circuit unit 605 are not limited to the circuit arrangement shown in the drawing, and the customer's requirements or the manufacturer's design matters It will be apparent to those skilled in the art that the position can be changed according to the above.

  A micro LED panel 300 is flip-chip bonded on such a CMOS backplane 600 to form a second type micro LED display device. At this time, the second type micro LED display device can be manufactured up to 1.22 inches.

  Since the first type micro LED display device and the second type micro LED display device only need to be changed in the left / right position on the same manufacturing process, no additional process is required, and the driving software is also up / It is applicable only by the development of a single software with the bottom, left / right symmetry option. Hereinafter, it is shown that the size of the display can be expanded by combining the first type micro LED display device and the second type micro LED display device.

FIG. 18 illustrates a micro LED display device according to an embodiment of the present invention.
Referring to FIG. 18, a micro LED display apparatus 1000 according to an embodiment of the present invention includes a micro LED panel 200, a first type CMOS backplane 500, and bumps 1010. At this time, the first type CMOS backplane 500 includes an active matrix circuit unit 505 and control circuit units 510 to 580 arranged in a region adjacent to the left side and the lower side of the active matrix circuit unit 505 (in plan view). Including.

  The micro LED panel 200 includes a plurality of micro LED pixels 280, and the CMOS backplane 500 includes a plurality of CMOS cells 501 corresponding to each of the micro LED pixels for individually driving the plurality of micro LED pixels. At this time, the pixel region of the micro LED panel 200 corresponds to the AM (active matrix) region of the CMOS backplane 500.

  The bump 1010 electrically connects each of the micro LED pixels 280 and the CMOS cell 501 corresponding to each of the micro LED pixels 280 in a state where the micro LED pixel 280 and the CMOS cell 501 are arranged to face each other (FIG. 18A). (FIG. 18B).

  If the manufacturing process of such a micro LED display device 1000 is briefly seen, first, a plurality of bumps 1010 are arranged above the CMOS cell 501 and the common cell 502 of the CMOS backplane 500 (FIG. 18A). . Then, the CMOS backplane 500 and the micro LED panel 200 in a state where the plurality of bumps 1010 are arranged face each other so that the CMOS cells 501 and the micro LED pixels 280 are brought into close contact with each other and then heated. Then, the plurality of bumps 1010 are once melted, whereby the CMOS cell 501 and the corresponding micro LED pixel 280 are electrically connected, and the common cell 502 and the corresponding common electrode 260 of the micro LED panel 200 are connected. Are electrically connected (FIG. 18B).

  On the other hand, in the present embodiment, the micro LED panel 200 of FIG. 8 is exemplified as being used in the micro LED display device 1000, but the present invention is not limited to this, and the micro LED panel 100 of FIG. It will be apparent to those skilled in the art that the display device 1000 may be used.

FIG. 19 illustrates a micro LED display device according to another embodiment of the present invention.
Referring to FIG. 19, a micro LED display device 1100 according to another embodiment of the present invention includes a micro LED panel 300, a second type CMOS backplane 600 and bumps 1110. At this time, the second type CMOS backplane 600 includes an active matrix circuit unit 605 and control circuit units 610 to 680 disposed in regions adjacent to the right side and the lower side of the active matrix circuit unit 605.

  The micro LED panel 300 includes a plurality of micro LED pixels 380, and the CMOS backplane 600 includes a plurality of CMOS cells 601 corresponding to each of the micro LED pixels in order to individually drive each of the plurality of micro LED pixels. The bumps 1110 connect each of the micro LED pixels 280 and the CMOS cell 601 corresponding to each of the micro LED pixels 280 in a state where the micro LED pixel 380 and the CMOS cell 601 are arranged to face each other (FIG. 19A). Electrical connection is made (FIG. 19B).

  If the manufacturing process of such a micro LED display device 1100 is briefly seen, first, a plurality of bumps 1110 are disposed on the CMOS cells 601 and the common cells 602 of the CMOS backplane 600. Then, the CMOS back plane 600 and the micro LED panel 200 in a state where the plurality of bumps 1110 are arranged are brought into close contact with each other so that the CMOS cells 601 and the micro LED pixels 280 are in close contact with each other, and then heated. Then, the plurality of bumps 1110 are once melted, whereby the CMOS cell 601 and the corresponding micro LED pixel 280 are electrically connected, and the common cell 602 and the corresponding common electrode 260 of the micro LED panel 200 are electrically connected. Connected.

  Similarly, in the present embodiment, the micro LED panel 300 is used in the micro LED display device 1100. However, the present invention is not limited to this. For example, the micro LED panel 100 of FIG. It will be apparent to those skilled in the art that the device 1100 may be used.

FIG. 20 is a diagram for explaining a micro LED display device in which the display size is expanded twice in the horizontal direction.
Referring to FIG. 20, the first type micro LED display device 1000 and the second type micro LED display device 1100 are arranged in the horizontal direction (ie, horizontal direction) in plan view to double the size of the display. The micro LED display device 10 extended to is realized.

  The expanded micro LED display device 10 includes a first display region (or first display panel) of the first type micro LED display device 1000 and a second display region (or second) of the second type micro LED display device 1100. Display panel) so as to face each other. At this time, the interval between the first display area and the second display area is minimized.

As an example, the interval (or distance, d) between the first display area and the second display area is determined by the following general formula 1.
[Equation 1]
d = 40 + 2α + β (general formula 1)

  Here, 40 (mm) is the sum of the width (20 mm) of the end region of the first CMOS backplane and the width (20 mm) of the end region of the second CMOS backplane, and a (mm) is sawing (chip). B) (mm) is a module assembly margin.

  As shown in FIGS. 8 and 9, when a common electrode (that is, an n-electrode) is not formed at a connection portion between the first display area and the second display area, The interval between the end pixels of the two display areas is configured to correspond to a pixel pitch. If the gap between the pixels is larger than the pixel pitch, the gap can be minimized to a size of several μm that cannot be recognized by human vision using an optical system.

  On the other hand, as shown in FIGS. 1 and 2, when a common electrode (that is, an n-electrode) is formed at a connection portion between the first display region and the second display region, the connection excluding the common electrode. The interval between the portions (gap) is configured to correspond to the pixel pitch. Similarly, when the gap between the connecting portions is larger than the pixel pitch, the gap can be minimized to a size of several μm that cannot be recognized by human vision using an optical system.

  In this way, the first type micro LED display device 1000 and the second type micro LED display device 1100 can be coupled in the horizontal direction to expand the size of the display twice.

FIG. 21 is a diagram illustrating a micro LED display device in which the display size is doubled in the vertical direction (that is, the vertical direction) in plan view.
Referring to FIG. 21, the first-type micro LED display device 1000 and the second-type micro LED display device 1100 are arranged in the vertical direction (that is, in the vertical direction) in plan view to double the display size. The micro LED display device 20 is realized.

  The expanded micro LED display device 20 is configured such that the first display region of the first type micro LED display device 1000 and the second display region of the second type micro LED display device 1100 face each other. At this time, the interval between the first display area and the second display area is minimized. As an example, the interval (d) between the first display area and the second display area is determined by the general formula 1.

  As shown in FIGS. 8 and 9, when a common electrode (that is, an n-electrode) is not formed at a connection portion between the first display area and the second display area, The interval between the end pixels of the two display areas is configured to correspond to the pixel pitch. On the other hand, as shown in FIGS. 1 and 2, when a common electrode (that is, an n-electrode) is formed at a connection portion between the first display region and the second display region, the connection excluding the common electrode. The interval between the portions (gap) is configured to correspond to the pixel pitch.

  In this way, the first type micro LED display device 1000 and the second type micro LED display device 1100 can be coupled in the vertical direction to double the size of the display.

FIG. 22 is a diagram for explaining a micro LED display device in which the size of the display is expanded four times.
Referring to FIG. 22, two first-type micro LED display devices 1000 and two second-type micro LED display devices 1100 are arranged in a matrix to expand the display size four times. The LED display device 30 is realized.

  In the matrix arrangement, the first type of micro LED display device 1000 is positioned in the first diagonal direction of the extended micro LED display device 30, and the second type of micro LED display device 1100 is an extended micro LED display device. It can be located in 30 second diagonal directions.

  Any one of the first type micro LED display devices 1000 positioned in the first diagonal direction may be disposed by rotating the other micro LED display device 1000 of the same type by 180 degrees. In addition, any one of the second type micro LED display devices 1100 positioned in the second diagonal direction may be disposed by rotating the other micro LED display device 1100 of the same type by 180 degrees.

  The expanded micro LED module 30 may be configured such that the first display area of the first type micro LED module 1000 and the second display area of the second type micro LED module 1100 face each other. At this time, the distance between the first display area and the second display area can be minimized. As an example, the interval (d) between the first display area and the second display area is determined by the general formula 1.

  As shown in FIGS. 8 and 9, when a common electrode (that is, an n-electrode) is not formed at a connection portion between the first display area and the second display area, The gap (gap) between the two display regions and the end pixel corresponds to the pixel pitch. On the other hand, as shown in FIGS. 1 and 2, when a common electrode (that is, an n-electrode) is formed at the connection portion between the first display region and the second display region, the connection portion excluding the common electrode. Is configured to correspond to the pixel pitch.

  As described above, the size of the display can be expanded four times through the change of direction and combination of the first type micro LED display device 1000 and the second type micro LED display device 1100.

  Although specific embodiments of the present invention have been described above, it goes without saying that various modifications can be made without departing from the scope of the present invention. Therefore, the scope of the present invention is not limited to the described embodiments, but must be determined not only by the claims described below, but also by the equivalents of the claims.

10, 20, 30 ... micro LED display device 100, 200 ... micro LED panel, micro LED array 110, 210 ... growth substrate 120, 220 ... first conductivity type semiconductor layer 130, 230 ... Active layer 140, 240 ... 2nd conductivity type semiconductor layer 150, 250, 350 ... 2nd conductivity type metal layer 160, 260, 360 ... 1st conductivity type metal layer 170, 270 ... Passivation Layers 180, 280, 380... Micro LED pixels 400, 500, 600... CMOS backplane 401, 501, 601... CMOS cells 405, 505, 605... Active matrix circuit portion 410 , 510, 610... Scan driver 420, 20, 620 ... 1st data drive part 430, 530, 630 ... 2nd data drive part 440, 540, 640 ... Gamma voltage generation part 450, 550, 650 ... Timing control part 460, 560 , 660 ... Scan signal detection pad unit 470, 570, 670 ... Data output detection pad unit 480, 580, 680 ... Input pad unit 1000, 1100 ... Micro LED display device 1010, 1110 ... bump

In order to achieve the above or other objects, according to one aspect of the present invention, a plurality of micro LED pixels are arranged in rows and columns, and the micro LED panel is rectangular in a plan view, and the plurality of micro LED pixels. A micro LED driving substrate including an AM (Active Matrix, Active Matrix) circuit unit including a plurality of CMOS cells corresponding to the above and a control circuit unit disposed outside the AM circuit unit, and the control circuit The part is disposed along two adjacent sides of the four sides of the micro LED panel, functions as a common electrode of the plurality of micro LED pixels, and is formed along an outline of the micro LED panel. It further includes a conductive metal layer, and is positioned on two sides of the micro LED panel according to the arrangement of the control circuit unit. There is provided a micro LED display device using the first conductive metal layer .

Claims (12)

A micro LED display device,
An AM (Active Matrix, active matrix) circuit unit including a micro LED panel having a rectangular shape in a plan view in which a plurality of micro LED pixels are arranged in rows and columns, and a plurality of CMOS cells corresponding to the plurality of micro LED pixels; A micro LED driving substrate including a control circuit unit disposed outside the AM circuit unit,
The micro LED display device, wherein the control circuit unit is disposed along two adjacent sides of the four sides of the micro LED panel.   The micro LED display device of claim 1, further comprising a bump for electrically connecting the plurality of micro LED pixels and the plurality of CMOS cells.   The micro LED display device according to claim 1, wherein the micro LED panel is coupled to the micro LED driving substrate by flip chip bonding.   The plurality of micro LED pixels are formed by sequentially growing a first conductive type semiconductor layer, an active layer, and a second conductive type semiconductor layer on a substrate and then etching, and the vertical structure of the plurality of micro LED pixels is: The first conductive type semiconductor layer, the active layer, and the second conductive type semiconductor layer are included in order, and the active layer and the second conductive type semiconductor layer are removed from the portion where the plurality of micro LED pixels are not formed. The micro LED display device according to claim 1, wherein the type semiconductor layer is exposed.   A first conductive metal layer is formed on the first conductive semiconductor layer in a portion where the plurality of micro LED pixels are not formed so as to be separated from the plurality of micro LED pixels. The micro LED display device according to claim 4.   The micro LED display device of claim 5, wherein the first conductive metal layer is formed on the first conductive semiconductor layer along an outline of the micro LED panel.   The micro LED display device of claim 5, wherein the first conductive metal layer functions as a common electrode of the plurality of micro LED pixels.   The micro LED driving substrate includes a common cell formed to correspond to the first conductive type metal layer, and the first conductive type metal layer and the common cell are electrically connected by a bump. The micro LED display device according to claim 5.   The first conductivity type metal layer is located on the four sides of the micro LED panel as a common electrode, and the first conductivity type metal layer located on the two sides of the micro LED panel is used according to the arrangement of the control circuit unit. The micro LED display device according to claim 8, wherein:   The micro LED display device of claim 4, wherein the first conductivity type is n-type and the second conductivity type is p-type.   The bumps are formed in each of the plurality of CMOS cells, and are melted by heating, whereby each of the plurality of CMOS cells and a micro LED pixel corresponding to each of the plurality of CMOS cells are electrically connected. The micro LED display device according to claim 2, wherein: The control circuit unit includes at least one of a scan driver, a first data driver, a second data driver, a gamma voltage generator, a timing controller, a scan signal detection pad unit, a data output detection pad unit, and an input pad unit. The micro LED display device according to claim 1, comprising:

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